This invention relates generally to turbomachinery, and specifically to stator vanes for the compressor, turbine or fan section of a gas turbine engine. In particular, the invention concerns a stator vane airfoil with axial and circumferential endwall contouring.
Gas turbine engines provide reliable, efficient power for a wide range of applications, including aviation and industrial power generation. Modern designs are typically built around a power core made up of a compressor, combustor and turbine section, arranged in flow series with an upstream inlet and downstream exhaust.
The compressor section compresses air from the inlet, which is mixed with fuel in the combustor and ignited to generate hot combustion gas. The turbine section extracts energy from the expanding combustion gas, and drives the compressor via a common shaft. Energy is delivered in the form of rotational energy in the shaft, reactive thrust from the exhaust, or both.
Small-scale gas turbine engines generally utilize a one-spool design, with co-rotating compressor and turbine sections. Larger-scale combustion turbines, jet engines and industrial gas turbines (IGTs) are typically arranged into a number of coaxially nested spools, which operate at different pressures and temperatures, and rotate at different speeds.
The individual compressor and turbine sections in each spool are subdivided into a number of stages, which are formed of alternating rows of rotor blade and stator vane airfoils. The airfoils are shaped to turn the working fluid flow, and to generate lift for conversion to rotational energy in the turbine.
Aviation applications include turbojet, turbofan, turboprop and turboshaft configurations. Turbojets are an older design, in which thrust is generated primarily from the exhaust. Modern fixed-wing aircraft typically employ turbofan and turboprop engines, in which the low pressure spool is coupled to a propulsion fan or propeller. Turboshaft engines are used on rotary-wing aircraft, including helicopters.
Across these different gas turbine applications, engine performance depends strongly on precise flow control over the stator vane airfoils. Flow control, in turn, depends not only on airfoil design, but also on the structure of the adjacent flowpath, as defined along the inner and outer endwalls of the flow duct, adjacent the airfoil surfaces.